This invention relates to the field of child restraint systems for controlling the tension and fit of a restraint harness about a child in a child seat. Several known pertinent references are commonly owned U.S. Pat. Nos. 5,380,066 and 5,779,319, and U.S. Pat. No. 4,688,849, the disclosures of which are incorporated herein by reference. The child restraint system comprises a retractor assembly capable of both automatic and manual adjustment, including incremental adjustment or ratcheting, of the restraint system's restraint harness. A reference pertinent to such incremental adjustment is U.S. Pat. No. 4,886,315, the disclosure of which is incorporated herein by reference.
The occupant restraint system disclosed herein comprises one or more of the features identified in the various claims appended to this application and combinations of such features as well as one or more of the following features or combinations thereof. A child seat is equipped with a three-point or a five-point restraint system comprising a restraint harness or assembly, a buckle, one or more tongues, a retractor, which may be an automatic retractor, and a manual tensioning device. The restraint system may be any suitable restraint system, including without limitation a three-point, a four-point, or a five-point restraint system. Illustratively, in the case of a five-point restraint system, the restraint harness comprises a pair of lap and shoulder portions, and a retraction portion. The restraint harness may be any flexible or semi-flexible member such as a web, a rope, a belt and the like. The buckle is attached to the seat and the tongues are movably disposed on the restraint harness and are lockingly and releasably engageable with the buckle to construct the five-point restraint. In the alternative, a pair of buckles may be movably disposed on the restraint harness and a tongue may be attached to the seat for releasable engagement with the buckles. As noted, alternative restraint systems, including for example and without limitation a three-point or a four-point restraint system, may be used instead of a five-point restraint system. The retractor comprises a spool having ratchet wheels or flanges at each end thereof. The spool may be coupled to a shaft, which in turn is movably coupled or mounted to a frame, as for example and without limitation between a pair of spaced apart plates. The frame may be carried by or mounted to the seat, for example to the front, the back, the side or the underside of the seat. The retraction portion of the harness is wound about and may but need not be attached to the spool.
A spool bias member is disposed between the spool and the frame and tends to urge the spool to move in a retracting or take-up direction to withdraw the retraction portion onto the spool to take up the slack in the harness to tighten the harness. A stop member, for example a pawl, movably mounted between the spaced-apart plates may engage the teeth of the ratchet wheel to inhibit movement of the spool in the retracting direction and to check, prevent or stop movement of the spool in a generally opposite pay-out direction. A stop bias member may urge the stop member into engagement and have a force or bias that counterbalances that of the spool bias member in normal or steady state conditions. The balanced or steady-state condition may be overcome either by manually rotating the spool in the retracting or take-up direction, or by directly moving the stop member away from engagement with the flange or ratchet wheel. In the instance of rotating the spool, the shaft may comprise an extension that allows the spool to be rotated in the take-up or retracting direction to further withdraw the retraction portion and wrap it about the spool to further decrease the operable length of the retraction portion and thereby tighten the harness around an occupant. The shaft or tensioning member may have a knob or actuation piece that facilitates the manual movement or rotation of the shaft. When the tensioning member or knob rotates the spool and ratchet wheel in the retracting direction, the teeth move or cam up the stop member which moves away from the teeth as the stop bias member yields to the rotation and camming or ratcheting forces. In this manner, the restraint member may incrementally be tightened or ratcheted by the described movement of the spool or tensioning member. In the instance of moving the stop member away from the spool, a release member may be actuated and held in the actuated position to move the stop member away from the spool, which would allow the spool bias member to urge the spool to rotate in the retracting or take-up direction but also yield to an external force pulling the restraint harness outwardly away from the spool in the pay-out direction which is generally opposite to the take-up or retracting direction. A pair of retractors, or more than two retractors, could be used as well. The components of the system may be fashioned from any suitable metallic, non-metallic, or composite material. These and other features of the present invention will become more apparent from the following description of the illustrative embodiments.